enable mod_rewrite in default configuration

install/vst-install-ubuntu.sh

@@ -456,6 +456,7 @@ chmod a+x /var/log/apache2
 chmod 640 /var/log/apache2/access.log
 chmod 640 /var/log/apache2/error.log
 chmod 751 /var/log/apache2/domains
+a2enmod rewrite
 a2enmod suexec
 echo -e "/home\npublic_html/cgi-bin" > /etc/apache2/suexec/www-data
 update-rc.d apache2 defaults